Calk gun



Nov. 21, 1939. s, E E 2,180,978-

CALK GUN Filed March 2, 1939 /Nl/E/VTO/?: SAMUEL CREWE' TTORNEX Patented Nov. 2i, 1939 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to calk guns and particularly to the ratchet mechanisms in them which operate the discharging piston.

As conducive to a clearer understanding of this invention it may be well to point out that calking compounds are viscous substances and are generally ejected through the gun nozzle with a pressure of several hundred pounds. The substance also is plastic and (somewhat elastic so that it compresses considerably under this pressure. In operation, if the ejecting pressure is suddenly stopped and the nozzle vent simultaneously made unobstructed, the calk continues to ooze out of the gun because of the compression and pressure stored within the gun. This not only causes considerable waste of material but causes the loss of time required to refill the guns more often than otherwise.

Most guns designed for emitting calk have some means for releasing the ratchet mechanism so that the piston may be drawn backward to release the internal pressure and thereby prevent the overflow of the calk. All of them, however, require some extra manual operation or releasing manipulation which is not always convenient to perform. Quite frequently the gun must be operated with one hand, the operator often needing the other hand to secure his position on some ladder or scaffold.

The instant invention relates particularly to the Ratchet mechanism described in my Patent No. 1,883,767 granted October 18, 1932, and to the mechanism used with the Cartridge for caulking guns described in my Patent No. 2,111,- 582 which was granted March 22, 1938.

It is therefore a primary object of this invention to provide a ratchet mechanism with an automatic back pressure release.

Another object of the invention is to provide such device with a release mechanism which does not change or interfere wtih the regular or customary operation of the gun.

A further object is to construct a simple ratchet mechanism and equip it with an automatic or a manual release which is economical to construct and eflicient in its operation.

These and other objects and features of the invention will become apparent from a study of the following description and claims together with the accompanying drawing in which like parts are designated by like reference characters and wherein:

Figure 1 is a side elevation of a calking gun, parts of which are broken away to show details of this invention. This view shows normal position of the parts;

Figure 2 is a cross-sectional view of the ratchet mechanism taken along the lines and in the direction of the arrows 2-2 of the Figure 1;

Figure 8 is a side view of the ratchet mechanism showing relative positions of parts when the ratchet-bar is free to move and disengaged from the pawl or dog;

Figure 4 is a similar view showing position of parts after the ratchet-bar has been moved forward from the position shown in Figure 1 and about to be locked in place; and

Figure 5 is a similar view showing position of ratchet-bar locked against rearward movement and ready to be projected forward once more.

The comprehensive view of Figure 1 shows a calking gun having a cylinder or barrel, a nozzle member and a ratchet mechanism.

The barrel l0 consists of a metal tube open at both ends. The forward end is provided with a removable and interchangeable nozzle II. The rear end is provided with external threads for convenient attachment to the ratchet mechanism hereinafter described in detail.

The Figure 1 also shows a removable cartridge l2 containing calk, which cartridge is specifically described in my Patent No. 2,111,582 dated March 22, 1938.

The ratchet mechanism consists of a hollow frame 20 to which is attached or integrally made a part thereof, the handle 2i and the internally threaded cup 22, which cup engages the rear end of the barrel M.

The hollow frame 20 has parallel side walls 23,

a rear wall 24 and a top cover 25 joining the two side walls 23 and the cup 22. Slightly above the handle 2| and a little forward of it, there is a. horizontal primary pivot pin '26 which is supported by the walls 23. Between the walls 23 and mounted on the pins 25 is an operating lever and between the two walls 3! of the lever and on the primary pivot pin 26 there is a small roller 21.

The rear wall 24 and the cup 22 each have rectangular openings 32 and 33 respectively through which there passes a ratchet-bar as it moves on the pivot pin roller 21. The rear wall 24 and the top cover 25 do not come together but instead are separated and form a corner opening 28 in the frame 20.

The operating lever 30 is provided wtih a secondary pivot pin 34 on which there is mounted a pawl 35. The pawl extends longitudinally and in line with the ratchet-bar 50. The forward side of the operating lever, the portion which connects its walls 3| has an opening 36 to 'acthe minor pin 33 which also extends through the walls SI of "the operating lever.

The lower end of the operating lever is provided with another pin 40, which supports within the lever a conventional spring 4|, one end of which 'is in the hollow'portion of the lever 30" and the other-end of which is in the hollow portion of the handle 2|. The two parts 2!. and 30 together form a conventional squeeze type grip assembly.

The top surface of the ratchet-bar 50 is provided with a series of upwardly projecting teeth 5|, which are engaged by the pawl detent 36 and the dog member 45 which will be described in detail hereinafter. The rearward end of the bar 50 is. provided wth-a simple cross-bar 52 which serves as a grip. The forward end of the ratchet-bar 50 has a special piston or plunger device 53 thereon which serves to eject the calk out of the cartridge l2 previously referred to.

The novelty of this invention lies primarily in the construction of the pawl member and dog member 35 and 45 respectively.

The pawl 35 consists of a solid piece of metal shaped somewhat to resemble a leg. In approximately its center there is a lateral hole through which there extends the secondary pivot pin 34. Forward of this lateral hole there is a foot-like portion which is designated as a detent 36 and which portion engages the teeth 5| of the ratchet-bar 56 in the ordinary manner. The heel of the foot-like portion engages the spring 31 and is pressed downward. Rearward of the lateral hole there is the calf-like portion which is herein termed the wedge 39, the upper oblique surface of which functions in the same manner as an ordinary cam. The pawl 35 is so positioned on the operating lever 30 and is so restricted in its movements that, when the bottom of the operating lever 30 is at its most forward position (in-1 dicated'by character 300), it can entirely clear the serrated ratchet-bar 50.

The dog member45 consists of a block of metal rectangular in general appearance. Its upper end projects through the corner opening 28 and is provided with a simple knob 46 to facilitate manual release should it become necessary in.

emergencies. The lower end of the dog member is tapered laterally and forms'the pick 41 which engages one of the notches of the serrated bar 50. The inside tapered surface 48 just above and forward of the pick 41 is specially beveled to form a surface which will co-act with the wedge 39. Actually the bevel 48 functions as a cam-follower so that pressure brought to bear against it raises the dog member so that the pick 41 is disengaged from the bar 50.

At about the center of the inside surface, about half way between the knob 46 and the bevel 48 is a lateral groove 49. A small spring 29 is mounted on the pin l9 and is supported bythe walls 23. One end of the spring 29 presses against the top cover 25 and the other end fits into the groove 49 and has a tendency to keep the dog 45 and the ratchet-bar 50 in constant engagement. The dog member '45 is held upright and in position by the two side walls 23, the rear wall 24, the edge of the top cover 26, the pin 44, and the spring 29.

The Figure 1 shows the operating lever 30 in the rest or normal position-with respect to the handle 2|. It also shows alternate positions in broken lines which positions represent the important stages of operation of the device. The alternate position indicated, by the character 30a corresponds with the Figure 5. At this stage the detent 36 is about to project the ratchet-bar 50 forward. The position indicated by the character 30b corresponds with the Figure 4. In this figure the bar 50 has just been moved forward and the dog 45 is about to engage one of the bar notches to prevent it from moving backward.

The position indicated by the character 30c corresponds with the Figure 3. This is the extraordinary position which engages the. pawl member cam with the dog member cam-follower so that the ratchet-bar 50 and the plunger device 53 may move backward of their own accord or by the pressure of the compressed calk within the barrel ill.

The extraordinary position 300 may be attained by either pushing the lever 30 forward or by allowing it to snap into that position by a quick release of the operating lever from the position 301). Either of these two motions may be performed with the one hand of the operator, the same hand that holds the gun.

The pressure and weight of the three springs 29, 31 and 4| are so balanced that when the operating lever 30 is allowed to move forward slightly in the regular manner the lever 30 will naturally stop at the normal position. This requirement is essential so as not to unnecessarily tire the operator or to exhaust the energy which otherwise would be used to restrain the lever 30 from going into the extraordinary position 300. It is only when extra weight is added to the spring 4| (special pressure forwardly applied to the lever 30), that it will outweigh or overbalance the tensions of the springs 29 and 31.

After the lever 30 reaches the extraordinary position 300, it is held there until released, by the small flange or step 43 on the bevel 48, which rests squarely on the shoulder 42 on the wedge 39.

Another feature of this invention is the construction which provides for conventional threaded engagement of the barrel [0 with the cup 22. This expedites the operation of the gun because if the barrel I0 is not tightly screwed on to the cup 22 but instead is allowed frequently to rotate therein, the grip member may be turned up, down or sideways with respect to the nozzle on the barrel, which adjustment makes it easier adaptations of the invention and those modifica- I tions are also considered to be within the broad scope of the invention as no limitations upon it are intended other than those imposed thereon by the scope of the appended claims.

I claim: 1. A ratchet mechanism, comprising in combination, a handle member, an operating lever pivoted to the handle member, a pawl member mounted on the operating lever, a ratchet-bar movable through the handle member, a tension means carried by the operating lever engaging the pawl member with the ratchet-bar, a dog member mounted on the handle member engageable with the ratchet-bar, and a means on the said pawl member for disengaging the said dog member.

2. A ratchet mechanism, comprising in combination, a hollow frame member, a hollow handle integral with the frame member having a primary pivot pin supported in the walls thereof,

otally mounted on the said secondary pivot pin, a spring carried by the operating lever resisting movement of the pawl member, a dog member mounted in the hollow of the frame member a longitudinally movable ratchet-bar guided in the walls of the frame member and in operative relation with the pawl and dog members, and a pawl and dog release means in the hollow frame member actuated by the said operating lever for disengaging the ratchet-bar therefrom.

3. In a calking gun of the type having a ratchet holding dog member actuated by a ratchet operating pawl member, a ratchet release comprising: a wedge integral with the pawl member, engageable with the dog member and having a shoulder thereon; and a tooth integral with the dog member and having a flange thereon engageable with the said shoulder.

SAMUEL CREWE. 

